/* s_traf.c
 *
 * Micropolis, Unix Version.  This game was released for the Unix platform
 * in or about 1990 and has been modified for inclusion in the One Laptop
 * Per Child program.  Copyright (C) 1989 - 2007 Electronic Arts Inc.  If
 * you need assistance with this program, you may contact:
 *   http://wiki.laptop.org/go/Micropolis  or email  micropolis@laptop.org.
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or (at
 * your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.  You should have received a
 * copy of the GNU General Public License along with this program.  If
 * not, see <http://www.gnu.org/licenses/>.
 * 
 *             ADDITIONAL TERMS per GNU GPL Section 7
 * 
 * No trademark or publicity rights are granted.  This license does NOT
 * give you any right, title or interest in the trademark SimCity or any
 * other Electronic Arts trademark.  You may not distribute any
 * modification of this program using the trademark SimCity or claim any
 * affliation or association with Electronic Arts Inc. or its employees.
 * 
 * Any propagation or conveyance of this program must include this
 * copyright notice and these terms.
 * 
 * If you convey this program (or any modifications of it) and assume
 * contractual liability for the program to recipients of it, you agree
 * to indemnify Electronic Arts for any liability that those contractual
 * assumptions impose on Electronic Arts.
 * 
 * You may not misrepresent the origins of this program; modified
 * versions of the program must be marked as such and not identified as
 * the original program.
 * 
 * This disclaimer supplements the one included in the General Public
 * License.  TO THE FULLEST EXTENT PERMISSIBLE UNDER APPLICABLE LAW, THIS
 * PROGRAM IS PROVIDED TO YOU "AS IS," WITH ALL FAULTS, WITHOUT WARRANTY
 * OF ANY KIND, AND YOUR USE IS AT YOUR SOLE RISK.  THE ENTIRE RISK OF
 * SATISFACTORY QUALITY AND PERFORMANCE RESIDES WITH YOU.  ELECTRONIC ARTS
 * DISCLAIMS ANY AND ALL EXPRESS, IMPLIED OR STATUTORY WARRANTIES,
 * INCLUDING IMPLIED WARRANTIES OF MERCHANTABILITY, SATISFACTORY QUALITY,
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 * WITH THIRD PARTY SOFTWARE OR THAT ANY ERRORS IN THE PROGRAM WILL BE
 * CORRECTED.  NO ORAL OR WRITTEN ADVICE PROVIDED BY ELECTRONIC ARTS OR
 * ANY AUTHORIZED REPRESENTATIVE SHALL CREATE A WARRANTY.  SOME
 * JURISDICTIONS DO NOT ALLOW THE EXCLUSION OF OR LIMITATIONS ON IMPLIED
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 * CONSUMER, SO SOME OR ALL OF THE ABOVE EXCLUSIONS AND LIMITATIONS MAY
 * NOT APPLY TO YOU.
 */
#include "sim.h"

/* Traffic Generation */

#define MAXDIS 30

short PosStackN, SMapXStack[MAXDIS + 1], SMapYStack[MAXDIS + 1];
short LDir;
short Zsource;
short TrafMaxX, TrafMaxY;
int RailCount;

int GetFromMap(int x);
int DriveDone(void);
int TryGo(int z);
int RoadOrRail(int x);
int RoadTest(int x);
int RailTest(int x);
void PullPos(void);
void SetTrafMem(void);
int TryDrive(void);


/* comefrom: DoIndustrial DoCommercial DoResidential */
int MakeTraf(int Zt)
{
    short xtem, ytem;

    xtem = SMapX;
    ytem = SMapY;
    Zsource = Zt;
    PosStackN = 0;
    RailCount = 0;

#if 0
    if((!Rand(2)) && FindPTele())
    {
/* printf("Telecommute!\n"); */
        return (TRUE);
    }
#endif

    if(FindPRoad())
    {                           /* look for road on zone perimeter */
        if(TryDrive())
        {                       /* attempt to drive somewhere */
            SetTrafMem();       /* if sucessful, inc trafdensity */
            SMapX = xtem;
            SMapY = ytem;
            return (TRUE);      /* traffic passed */
        }
        SMapX = xtem;
        SMapY = ytem;
        return (FALSE);         /* traffic failed */
    }
    else
        return (-1);            /* no road found */
}

int hasRailNearby()
{
    int count = 0;
    int x,y;

    for (x=SMapX-10; x<SMapX+10 ; x++)
    {
        for (y=SMapY-10; y<SMapY+10 ; y++)
        {
            if (TestBounds(x, y) && RailTest(Map[x][y]))
            {
                count++;
            }
        }
    }

    return count*2;
}

/* comefrom: MakeTraf */
void SetTrafMem(void)
{
    register short x, z;
    int ratio;

    if (PosStackN != 0)
        ratio = (RailCount*100)/(PosStackN);
    else
        ratio = 0;

    for(x = PosStackN; x > 0; x--)
    {
        PullPos();
        if(TestBounds(SMapX, SMapY))
        {
            z = Map[SMapX][SMapY];
            if(RoadTest(z))
            {
                SimSprite *sprite;

                z = TrfDensity[SMapX >> 1][SMapY >> 1];
                z += 50;
                z -= ratio/2;
                z -= hasRailNearby();
                if (z < 0)
                    z = 0;
                if((z > 240) && (!Rand(5)))
                {
                    z = 240;
                    TrafMaxX = SMapX << 4;
                    TrafMaxY = SMapY << 4;
                    if(((sprite = GetSprite(COP)) != NULL) && (sprite->control == -1))
                    {
                        sprite->dest_x = TrafMaxX;
                        sprite->dest_y = TrafMaxY;
                    }
                }
                TrfDensity[SMapX >> 1][SMapY >> 1] = z;
            }
        }
    }
}

/* comefrom: TryGo */
void PushPos(void)
{
    if (RailTest(Map[SMapX][SMapY]))
    {
        RailCount++;
    }
    PosStackN++;
    SMapXStack[PosStackN] = SMapX;
    SMapYStack[PosStackN] = SMapY;
}

/* comefrom: SetTrafMem */
void PullPos(void)
{
    SMapX = SMapXStack[PosStackN];
    SMapY = SMapYStack[PosStackN];
    PosStackN--;
}

/* comefrom: DoSPZone MakeTraf */
int FindPRoad(void)
{                               /* look for road on edges of zone   */
    static short PerimX[12] = { -1, 0, 1, 2, 2, 2, 1, 0, -1, -2, -2, -2 };
    static short PerimY[12] = { -2, -2, -2, -1, 0, 1, 2, 2, 2, 1, 0, -1 };
    register short tx, ty, z;

    for(z = 0; z < 12; z++)
    {
        tx = SMapX + PerimX[z];
        ty = SMapY + PerimY[z];
        if(TestBounds(tx, ty))
        {
            if(RoadOrRail(Map[tx][ty]))
            {
                SMapX = tx;
                SMapY = ty;
                return (TRUE);
            }
        }
    }
    return (FALSE);
}

int FindPRoadCheck(void)
{
    short x, y;
    int res;

    x = SMapX;
    y = SMapY;
    res = FindPRoad();
    SMapX = x;
    SMapY = y;
    return res;
}

int FindPTele(void)
{                               /* look for telecommunication on edges of zone */
    static short PerimX[12] = { -1, 0, 1, 2, 2, 2, 1, 0, -1, -2, -2, -2 };
    static short PerimY[12] = { -2, -2, -2, -1, 0, 1, 2, 2, 2, 1, 0, -1 };
    register short tx, ty, z, tile;

    for(z = 0; z < 12; z++)
    {
        tx = SMapX + PerimX[z];
        ty = SMapY + PerimY[z];
        if(TestBounds(tx, ty))
        {
            tile = Map[tx][ty] & LOMASK;
            if((tile >= TELEBASE) && (tile <= TELELAST))
            {
                return (TRUE);
            }
        }
    }
    return (FALSE);
}

/* comefrom: MakeTraf */
int TryDrive(void)
{
    short z;

    LDir = 5;
    for(z = 0; z < MAXDIS; z++)
    {                           /* Maximum distance to try */
        if(TryGo(z))
        {                       /* if it got a road */
            if(DriveDone())     /* if destination is reached */
                return (TRUE);  /* pass */
        }
        else
        {
            if(PosStackN)
            {                   /* deadend , backup */
                PosStackN--;
                z += 3;
            }
            else
                return (FALSE); /* give up at start  */
        }
    }
    return (FALSE);             /* gone maxdis */
}

/* comefrom: TryDrive */
int TryGo(int z)
{
    short x, rdir, realdir;
    int tmp;
    int dens;

#if 0
    rdir = Rand(3);             /* XXX: Heaviest user of Rand */
#else
    rdir = Rand16() & 3;
#endif
    for(x = rdir; x < (rdir + 4); x++)
    {                           /* for the 4 directions */
        realdir = x & 3;
        if(realdir == LDir)
            continue;           /* skip last direction */
        tmp = GetFromMap(realdir);
        if(RailTest(tmp))
        {
            MoveMapSim(realdir);
            LDir = (realdir + 2) & 3;
            if(z & 1)           /* save pos every other move */
                PushPos();
            return (TRUE);
        }
    }

    for(x = rdir; x < (rdir + 4); x++)
    {                           /* for the 4 directions */
        realdir = x & 3;
        if(realdir == LDir)
            continue;           /* skip last direction */
        tmp = GetFromMap(realdir);
        if(RoadTest(tmp))
        {
            dens = TrfDensity[SMapX >> 1][SMapY >> 1];
            if (dens > 200 && Rand16() & 1) continue;
            if (dens > 100 && Rand16() & 1) continue;
            if (dens > 75 && Rand16() & 1) continue;
            MoveMapSim(realdir);
            LDir = (realdir + 2) & 3;
            if(z & 1)           /* save pos every other move */
                PushPos();
            return (TRUE);
        }
    }
    return (FALSE);
}

/* comefrom: TryGo DriveDone */
int GetFromMap(int x)
{
    switch (x)
    {
        case 0:
            if(SMapY > 0)
                return (Map[SMapX][SMapY - 1] & LOMASK);
            return (FALSE);
        case 1:
            if(SMapX < (WORLD_X - 1))
                return (Map[SMapX + 1][SMapY] & LOMASK);
            return (FALSE);
        case 2:
            if(SMapY < (WORLD_Y - 1))
                return (Map[SMapX][SMapY + 1] & LOMASK);
            return (FALSE);
        case 3:
            if(SMapX > 0)
                return (Map[SMapX - 1][SMapY] & LOMASK);
            return (FALSE);
        default:
            return (FALSE);
    }
}

/* comefrom: TryDrive */
int DriveDone(void)
{
    static short TARGL[3] = { COMBASE, LHTHR, LHTHR };
    static short TARGH[3] = { NUCLEAR, PORT, COMBASE }; /* for destinations */
#if 0
    register short x;
#endif
    register short z, l, h;

/* unwound -Don */
#if 0
    for(x = 0; x < 4; x++)
    {                           /* R>C C>I I>R  */
        z = GetFromMap(x);
        if((z >= TARGL[Zsource]) && (z <= TARGH[Zsource]))
            return (TRUE);
    }
#else
    l = TARGL[Zsource];
    h = TARGH[Zsource];

    if(SMapY > 0)
    {
        z = Map[SMapX][SMapY - 1] & LOMASK;
        if((z >= l) && (z <= h))
            return (TRUE);
    }
    if(SMapX < (WORLD_X - 1))
    {
        z = Map[SMapX + 1][SMapY] & LOMASK;
        if((z >= l) && (z <= h))
            return (TRUE);
    }
    if(SMapY < (WORLD_Y - 1))
    {
        z = Map[SMapX][SMapY + 1] & LOMASK;
        if((z >= l) && (z <= h))
            return (TRUE);
    }
    if(SMapX > 0)
    {
        z = Map[SMapX - 1][SMapY] & LOMASK;
        if((z >= l) && (z <= h))
            return (TRUE);
    }
#endif

    return (FALSE);
}

/* comefrom: TryGo FindPRoad */
// #define ROADBASE	    64
// #define POWERBASE	208
// #define RAILHPOWERV	221
// #define LASTRAIL	    238
int RoadOrRail(int x)
{
    return (RoadTest(x) || RailTest(x));
}

int RoadTest(int x)
{
    x = x & LOMASK;
    if(x < ROADBASE || x >= POWERBASE)
        return (FALSE);
    return (TRUE);
}

int RailTest(int x)
{
    x = x & LOMASK;
    if(x < RAILHPOWERV || x > LASTRAIL)
        return (FALSE);
    return (TRUE);
}
